Any tips on using these USB mic models with an Apple iPad?
An externally-powered USB hub is needed. The PG27-USB and the PG42-USB need more current/power than the iPad can provide from its USB port. The symptom is that the iPad refuses to establish the data connection.
External USB hub of your choice and its power adapter
Apple iPad Camera Connection Kit - which is also useful USB audio devices
Apple iPad recording software, such as Garage Band for iPad
Make the connections in this order:
1. Connect the power adapter to the USB hub.
2. Plug the Shure USB microphone into the hub.
3. Attach the USB camera connector attachment to the end of the USB cable from the hub
4. Plug the connector into the iPad.
Failing to follow this order of connection may bring about an iPad error message.